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Finding the Fourth Proportional to 1,218.02, 1,680.62 and 686.86

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Solution

The fourth proportional to 1,218.02, 1,680.62 and 686.86 is: 947.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,218.02 : 1,680.62 = 686.86 : x
  2. Step 2: Convert to fraction form
    1,218.02/1,680.62 = 686.86/x
  3. Step 3: Cross multiply
    1,218.02x = 1,680.62 × 686.86
  4. Step 4: Simplify right side
    1,218.02x = 1,154,350.65
  5. Step 5: Solve for x
    x = 1,154,350.65/1,218.02
  6. Step 6: Final answer
    x = 947.73

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.